Kitty Pryde is a mutant with the ability to “phase” through solid matter by shifting her atoms through the spaces between the atoms of the object through which she is moving. Kitty can phase her clothing along with herself, and through practice has learned to phase other objects and people without harm to them. For all intents and purposes, Kitty is intangible whilst phasing, however she is still vulnerable to psionic or mystical attacks. Certain forms of energy can also disrupt her phased state.

When Kitty phases through an object with an electrical system, the process disrupts the system's workings. This includes the electrical impulses found in the human brain. Kitty can phase part or all of her body through another living being without harm to herself, though the other being can be rendered unconscious as a result. Kitty also has the potential to kill another being by phasing them into a solid object and then releasing them, causing them to solidify whilst still within the object.

Kitty passes through objects at the same rate of speed at which she is moving before phasing. Since she is unable to breathe while phasing, she can only continuously phase through solid objects - as when she travels underground - as long as she can hold her breath. Kitty can keep her phased form at rest in relation to the rotation of the Earth upon its axis, thus allowing her to assume a ground speed of the length of a football field and a half every second. Kitty can also walk on air whilst phasing.

Kitty has trained herself to reflexively assume a phased state at any indication of danger, such as a loud noise like a gunshot, in order to protect herself.

Abilities

Kitty possesses moderate expertise of the martial arts of the Japanese ninja and samurai. Kitty demonstrated great knowledge of ninja methods of combat when Ogun mentally possessed her. With the possession over, Kitty forgot the knowledge of ninja techniques he gave her, but retained the knowledge of Oriental methods of combat Wolverine taught her.
Kitty is also a genius in the computer sciences, and is highly skilled in the design and use of computer hardware. She is a competent driver of automobiles, a skilled pilot of piston and jet engine aircraft, and a competent pilot of certain advanced interstellar vehicles. Kitty also undertook ballet and modern dance training, speaks fluent Japanese, Russian, and the royal and standard languages of the alien Shi'ar, and has moderate expertise in Gaelic, Hebrew, and German.

Weapons

Kitty formerly used one of Wolverine's bone claws attached to her wrist.

Paraphernalia

Kitty possesses several volumes of "Destiny's Diaries," books written by the precognitive mutant Destiny on possible events of the future.

Katherine "Kitty" Pryde was a 13½-year old Jewish girl whose genius level intellect allowed her to take college-level courses despite her young age. Kitty led a fairly normal life until she began suffering headaches of steadily increasing intensity, which were a result of her emerging mutant power.

Kitty herself was unaware that she was a mutant until the afternoon that Emma Frost, then White Queen of the Hellfire Club, arrived to speak to her parents about enrolling Kitty in her Massachusetts Academy. During the visit, Kitty suffered her worst headache yet and went upstairs to her room. When the headache stopped, Kitty was surprised to find she was on the floor of her living room. She had unknowingly used her power to phase through solid matter for the first time, passing through her bed and floor into the room below.

Kitty as Ariel

After Frost left, Professor Charles Xavier arrived with three of the X-Men, his own team of mutant students who fought for peaceful coexistence between humans and mutants. Following an attack by the Hellfire Club during which Kitty helped the team, the X-Man Phoenix telepathically coerced Kitty's parents into allowing her to join Xavier's school, and she became the newest and youngest member of the X-Men. Kitty originally called herself Sprite, but later adopted the codename Ariel. Xavier also arranged for Kitty to be enrolled in dance classes at the studio of instructor Stevie Hunter.

Kitty quickly became a valuable member of the X-Men, proving her worth one Christmas Eve by single-handedly defeating one of the demonic N'Garai. Kitty formed a close friendship with both the X-Man Storm and the mutant sorceress Illyana Rasputin. The bond between Kitty and Illyana grew so strong that Kitty was eventually able to manifest the Soulsword, the ultimate expression of Illyana's magical nature.

Kitty also formed a romance with her teammate Piotr Rasputin (Colossus), and she gained a constant companion on an adventure in space in the form of a small alien dragon-like creature she named Lockheed. Kitty gained another close friend when she met Doug Ramsey, a fellow student in Stevie Hunter's dance class with whom she shared an affinity for computers. Doug's death on a mission with the New Mutants would prove to be the first of many personal losses Kitty would suffer.

After a visit to her recently divorced father, Carmen, Kitty learned that he had become involved with the Japanese Yakuza and followed him to Japan where she was captured and put under the mental control of Ogun, the martial arts master who had once been her teammate Wolverine's teacher. Using Kitty's body, Ogun attempted to kill Wolverine but failed. Wolverine then taught Kitty to become skilful enough in the martial arts to combat Ogun, and together they managed to exorcise Ogun's spirit. During the course of this adventure, Kitty took to calling herself Shadowcat.

While Colossus was away on Battleworld during what was to be called the Secret Wars, he became infatuated with an alien healer named Zsaji. Upon returning to Earth, he admitted his disloyalty to Kitty, severing their romance.

During the massacre of the underground community of mutants known as the Morlocks by the team of superhuman mutant assassins the Marauders, Kitty was injured by an energy spear hurled by the Marauder called Harpoon that adversely affected her powers. Unable to regain her solidity, Kitty was saved by the combined efforts of the European dictator Doctor Doom and his arch-rival, Reed Richards of the team of superhuman adventurers known as the Fantastic Four. However, she could now only maintain a solid form through concentration.

After witnessing the apparent death of the X-Men, Kitty helped form the British-based super-team Excalibur. During an inter-dimensional adventure, Kitty became separated from her teammates and, returning to her own Earth, she decided to give up the life of a costumed adventurer and attend college. However, unaccustomed as she was to the British educational system, Kitty was forced to enroll in St. Searle’s School for Girls. After helping save the school from closure, Kitty rejoined her recently returned teammates.

Months later, Kitty learned that Illyana was dying from the deadly mutant-killing Legacy Virus, a disease that targeted mutants. Kitty was present when Illyana finally succumbed to the disease, unaware that the young mutant's death bonded the Soulsword to her. Eventually the arcane magic's of the sword began to corrupt Kitty, and she surrendered the weapon to her then teammate Daytripper who in turn gave it to her mother, the gypsy sorceress Margali Szardos.

Soon after, Excalibur was approached by the clandestine organization known as Black Air for assistance on a mission to the island nation of Genosha. They were assigned a liaison in Pete Wisdom, an uncouth British mutant who regularly clashed with the outspoken Kitty. The pair eventually overcame their initial impressions of one another and fell in love. Wisdom even resigned from Black Air and joined Excalibur to be with Kitty.

Later, Kitty was recruited by the international law enforcement agency S.H.I.E.L.D. to repair the computer system of their flying headquarters. Kitty discovered the problem was due to Ogun’s spirit having infiltrated the computer system, and with the aid of Wolverine, she managed to purge Ogun's presence. During this time, Kitty was attracted to a S.H.I.E.L.D. intern her own age, and this made her begin to doubt her relationship with Wisdom. Soon after, she broke off their relationship.

Kitty remained a member of Excalibur until it disbanded whereupon she rejoined the X-Men. Soon after, an incident in Genosha caused Kitty to develop a rebellious attitude, reflected by her cutting her hair short, her more ferocious combat technique, and her taking to wielding one of Wolverine's broken bone claws in battle.

When Colossus sacrificed his life to release a cure for the Legacy Virus, his body was supposedly cremated, and Kitty scattered the ashes over his Russian farmland home. Mourning the loss of her old friend, and trying to live a normal life, Kitty left the X-men. She enrolled in the Robert A. Heinlein School for Engineering and Astrophysics in Chicago on a full scholarship, yet chose to live off campus and began working as a bartender for her neighbor at his establishment, the Belles of Hell. Kitty found herself unable to escape the ever-prevalent prejudice of humans, and she soon clashed with members of a student anti-mutant organization named Purity. Kitty was put on probation and was forced to attend mandatory counseling. During this time, Kitty faced her most difficult loss when she learned her father was amongst those killed in an attack on Genosha.

Kitty's battle against Purity continued after the organization attempted to frame her for the sabotage of a research experiment. A student meeting was called to debate the banning of either Purity or mutants from campus, but discussions were cut short by an attack by a new breed of mutant-hunting robotic Sentinels which were destroyed by Kitty with the help of former New Mutant Karma and Genoshan exchange student Shola Inkosi.

Kitty was later abducted by the mutant-hating Reverend Stryker to help expose the technological threat of the mutant retreat known as Mount Haven and its mysterious leader, Reverend Paul. Together, Stryker and Kitty discovered that Paul was an artificial intelligence who had killed the human townspeople and used microbial machines called nanites to transform the minds of the mutant residents from organic matter into cybernetic computers linked to his central consciousness. When Storm's team of X-Men arrived to find Kitty, Paul sought to transform them as well. Stryker attempted to use Kitty's power to disrupt electronics to destroy Paul, but he failed and Paul responded by transferring his consciousness into a global network. In an effort to safeguard his kind from Paul’s threat, Stryker merged with him in an attempt to teach him about humanity, and the town of Haven was buried by a volcanic eruption.

Soon after, Kitty assisted Storm’s team against the threat of mutant predator Elias Bogan. After Bogan was defeated, Kitty accompanied the team back to the mansion and was asked to remain as a member of Cyclops’ restructured X-Men. Peter Rasputin was discovered to be alive, his body secretly been stolen and resuscitated by Ord, an alien who had learned that an Earth mutant would be responsible for destroying his world. Kitty found Peter shortly before the X-Men's final battle with Ord, after which he rejoined the X-Men. After many years apart, Kitty and Peter reignited their romance.

During the crisis with the Hellfire Club, Kitty did exactly what Emma thought she would do. Kitty beat Emma and trapped her deep underground. Then Kitty was caught under a telepathic spell by Emma's evil version called Perfection. It gave Kitty the illusion that she and Colossus had a baby and the X-Men were taking it away to kill it because it was too dangerous. She was eventually lead to a box somewhere inside the school, she phased through it an took it out thinking it was her baby. Still not knowing anything, she actually freed an alien entity that contained Cassandra Nova's consciousness. Nova jumped over into Emma's mind and Emma manipulated Kitty into trying to shoot her to kill Nova. Kitty refuses to kill her and Nova then tries to leap into one of the students. Everything was then interrupted by SWORD and teleported to Breakworld.

While traveling to Breakworld, where as Agent Brand informs them is a missile pointed to earth which she needs the X-men to disable, Kitty is still feeling the after effects of Emma's mind game and as such rejects Peter. After their act in Brands ship and subsequently eject in one of the escape pods that comes a part in the air she holds on to Peter and phases. However as she phases through the first building she is affected by the strange Breakworld metal that is used and Peter then takes the brunt of their fall to the surface.

Not much later Kitty and Peter after fighting of many of the Breakworld inhabitants and soldiers, who are certain Peter is there to bring about the destruction of their world as was foretold. They are led to Aghanne, a former warrior of Breakworld who has compassion for her worlds sick and/or weak which is considered as close to sin for their race of warriors, by one of her men and are offer shelter for the night before they are to rendezvous with the others. It is there that they make love again after Kitty explains to a now confused Peter that they should live in the now.

Meeting up with the team their first attempt of reaching the missile is halted. Agent Brand also informs Kitty that Lockheed is in fact an intelligent alien species that was in fact their mole within the X-men in return for SWORD help with pressing issue back on his home world. Scott devises a plan B which includes him dying and being brought back to live by their enemy.
Kitty tries to approach Emma after Scott's death but is snidely shot down by the White Queen. Their second attempt is so successful that they manage to reach the missile but are unable to to disable it as their are no real remote control or control panels to do so. Kitty decides to phases through the missile and disrupt it's circuitry from within while only very short moments away from firing. After phasing through a mile of Break world metal Kitty reaches the center which, to her surprise is empty. As Beast concludes that the missile is in fact a bullet Kitty passes out as the bullet is fired. As everyone attempts to both stop the bullet and save Kitty, Emma contacts her to inform her of their efforts to get her out and ask her to phase out of the bullet. Kitty informs her that she feels sick as the metal somehow meshed with her and thus trapped her. Emma tells Kitty that their chances of stopping the bullet are not good and presses that Kitty try and phase out. Realizing what the likely outcome is Kitty accepts her fate ignoring Emma's attempts to reassure her that she will be rescued.

As the two women say their final words to each other Emma states that this was not what she had wanted for Kitty and Kitty replies with humor that if she recalled she was brought aboard to take Emma out. When she asks Emma if she was disappointed Emma responded with respect that she was astonished. With this, their rivalry that dated back to Emma's recruitment efforts of Kitty ended.

With the bullet quickly approaching and Earth's Mightiest Heroes being unable to stop it, Kitty summoned all her power and with superhuman effort, phased the entire bullet straight-through the planet. The bullet continued without losing any velocity into deep space. At that point, Emma lost all telepathic contact with Kitty.

Speculation between Dr. Strange, Reed Richards and other intellects believed that she had fused with the bullet, and that she was lost forever.
Abigail Brand revealed to Lockheed that Kitty Pryde was still alive inside the bullet, but how it was nearly impossible to break open the bullet, because it hardens when time goes by.

In an attempt to gain the X-Men's trust, Magneto goes to the top of Mt. Tamalpais where he focuses all of his powers to bring back the X-Men's long lost teammate. Magneto concentrates hard to change the direction of the metal bullet, in which Kitty Pryde is trapped in, and bring it to Earth safely. It is revealed that Magneto had encountered the bullet before, back when he and the High Evolutionary were trying to bring back Magneto's powers and save the mutant race. The High Evolutionary detected it and had found a mutant inside as well. The High Evolutionary told Magneto that he was able to recover the bullet, but Magneto chose to concentrate on what they were doing. He knew at that time it was Kitty who was inside the bullet, but decided to retrieve her back to Earth later, keeping it a secret it to himself. The X-Men discovered his plan and prepared for her arrival. Magneto successfully retrieved the bullet and cracked it open, bringing Kitty to the ground. When Kitty and Colossus tried to touch each other, it is revealed that she is trapped in her intangible form. The X-Men quickly place her in a protective chamber, with Colossus sitting by her side.